The present invention relates generally to electrostatic discharge protection devices and, more particularly, to electrostatic discharge protection devices suitable for use with electronic components containing electrical conductors or wires.
During the fabrication processes of conventional electronic components there may occur a build-up of electrostatic charges on device surfaces. When this electrostatic charge becomes substantial, an electrostatic discharge (ESD) may occur. The effects of an electrostatic discharge, which results in a substantial voltage spike, can permanently damage precision devices such as magnetoresistive (MR) heads used in magnetic storage devices.
Electrostatic charge may be produced when certain materials, such as plastics, are handled during manufacture. In an MR head, for example, the ESD may cause arcing across the edge of the insulating layer between the magnetic pole tips and adjacent conductive layers. This results in an erosion of the pole tips and degradation of the transducer, or may even cause destruction of the MR head.
U.S. Pat. No. 5,465,186 "Shorted magnetoresistive head leads for electrical overstress and electrostatic discharge protection during manufacture of a magnetic storage system," issued to Bajorek et al., discloses a MR sensor element in which the conductive leads are shorted together to provide a low resistance, conductive path bypassing the MR element so as to minimize electrical current through the MR element during discharge of static electrical charge. This approach, however, does not provide for the easy removal of the short circuit and requires changes to the process steps followed in fabrication of the MR head.
Further, if electrical testing of the electronic component is to be performed, the electrostatic discharge protection device must be removed. In most conventional ESD protection devices, the removal is permanent and leaves the electronic component vulnerable to ESD damage after testing has been completed. There does not appear to have been disclosed an electrostatic discharge protection device which provides for the electrical shorting of MR head elements without requiring process changes and which allows for the easy removal of the electrical shorting elements.
Other devices and methods of providing electrostatic discharge protection for various semiconductor packages are found in commonly assigned patents issued to David V. Cronin including: U.S. Pat. No. 5,108,299 "Electrostatic discharge protection devices for semiconductor chip packages," issued Apr. 28, 1992; U.S. Pat. No. 4,971,568 "Electrical connector with attachment for automatically shorting select conductors upon disconnection of connector," issued Sep. 20, 1990; U.S. Pat. No. 5,163,850 "Electrostatic discharge protection devices for semiconductor chip packages," issued Nov. 17, 1992; U.S. Pat. No. 5,164,880 "Electrostatic discharge protection device for printed circuit board," issued Nov. 17, 1992 and pending U.S. application Ser. Nos. 08/234,917 filed Apr. 28, 1994, and 08/278,024 and 08/278,063 both filed Jul. 20, 1994. These electrostatic discharge protection devices are most generally suitable for attachment to a connector or to a receptacle and not to the electrical conductors themselves. Thus, there remains the risk of damage from an ESD occurring on the electrical conductors.
Accordingly, it is an object of this invention to provide a device which serves to minimize ESD damage to electronic components containing electrical conductors.
It is another object of this invention to provide such a device which electrically connects to electrical conductors and may be temporarily disconnected to allow for electrical testing of the electronic component.
It is a further object of this invention to provide such a device which does not require extensive process changes in the fabrication of the electronic component. These and other objects of the invention will be obvious and will appear hereinafter.